Letter to the Editor about the article “Estimation of MBC: MIC Ratio of Herbal Extracts against Common Endodontic Pathogens”

Sir, It is with great interest that we have read the article entitled “Estimation of MBC: MIC Ratio of Herbal Extracts against Common Endodontic Pathogens” published in the Journal of Pharmacy and Bioallied Sciences.[1] This work aligns with the growing trend in dentistry that promotes the use of natural extracts in endodontics. We would like to congratulate the authors for their commendable work in exploring the antimicrobial efficacy of three essential oils (EOs): lemongrass oil, basil oil, peppermint oil, and a tea mixture extract against endodontic pathogens. For this purpose, the authors proposed simple in vitro methods to evaluate minimum inhibitory concentrations (MICs), minimum bactericidal concentrations (MBCs), and minimum fungicidal concentrations (MFCs). However, some methodological concerns may need to be highlighted for the sake of clarity and reproducibility. Firstly, regarding the herbal products used, the authors provided information on their commercial origin but did not specify the concentrations tested or the volumes used. Additionally, it was unclear whether the EOs were mixed with a surfactant such as DMSO (Dimethyl Sulfoxide) or Tween 80 (Polysorbate 80), or used alone. The use of these surfactants is crucial for improving bioavailability of the EOs and maintaining a homogeneous mixture with the bacterial inoculum, as the EOs are scarcely water-soluble.[2] Secondly, the authors utilized broth dilution method and subculturing technique to evaluate the antimicrobial activity of the herbal extract against several microorganisms as a quantitative approach. However, they didn’t specify the initial concentration of the bacterial inoculum tested in their study. Additionally, they did not mention the incubation conditions, such as temperature and incubation period, that are crucial for accurately interpreting results and ensuring reproducibility of the study. It is also important to highlight the necessity of proposing a qualitative approach, such as microscopy, when assessing the antimicrobial efficacy of an agent, as relying solely on culturing methods can be insufficient.[3] It would be appreciated if they provided precise numerical values for the MICs, MBCs, and MFCs corresponding to each microorganism for easier interpretation of the outcomes. While acknowledging the efforts and dedication involved in this study, additional methodological details would have been helpful for gaining a more thorough understanding of the results. Furthermore, these details would allow for more accurate comparisons across studies in the literature. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.